x-1\(\dfrac{1}{5}\)x=60%
<=>x-\(\dfrac{6}{5}\)x=\(\dfrac{60}{100}\)
<=>\(\dfrac{-1}{5}x=\dfrac{3}{5}\)
=>x=-3
\(x-1\dfrac{1}{5}x=60\%\\ 1x-\dfrac{6}{5}=\dfrac{3}{5}\\ x\left(1-\dfrac{6}{5}\right)=\dfrac{3}{5}\\ x\left(\dfrac{5}{5}-\dfrac{6}{5}\right)=\dfrac{3}{5}\\ x\dfrac{-1}{5}=\dfrac{3}{5}\\ x=\dfrac{3}{5}:\dfrac{-1}{5}\\ x=\dfrac{3}{5}.\dfrac{-5}{1}\\ x=-3\)
chúc bạn học tốt!!